The initial (1999) application for this IDDRC included separate cores in Neuropathology and Neuroscience, with the latter offering expertise in cell culture. As user needs evolved, it became apparent that these facilities should be merged into a single Cellular Neuroscience Core. This was accomplished in 1994 with Dr. Pleasure as the Director. He served in this capacity unfil 2001, when leadership passed to Dr. Jeffrey Golden, a pediatric neuropathologist with a primary interest in developmental disorders. Dr. Golden first joined CHOP in 1997 and immediately became engaged with the IDDRC, both as a user and as an Associate Director of the Cellular Neuroscience Core. Since its inception this Core has provided users with a diverse repertoire of state-of-the-art methods for visualizaion of the distribufions of gene products in normal, developing neural cells and in those undergoing various forms of degeneration and regenerafion. We have confinually and eagerly added new skills, instrumentafion and reagents to better serve our users' needs. In 1995, with the generous assistance of the Children's Hospital, we purchased a Leica confocal microscope to which we added inverted microscopy, stagemounted micromanipulators/microinjectors, and a stage-mounted environmental chamber, thus permitting prolonged observation and manipulation of living cells under physiological conditions. In this manner we offered 8-color capacity fluorescent imaging. Our institution paid for the apparatus and we used IDDRC funding to partially support a technician. We made several other notable technological additions to the Core repertoire, including in situ hybridization in both sections and whole embryos. Our general purpose has been not only to make available a technology, but a consultative sen/ice that facilitates implementation of the method as well as the interpretation of data. We adhered to this policy when we also added video-enhanced microscopy in order to better support IDDRC investigators in analyzing intracellular Ca2+ and Na+ as well as the estimate of mitochondrial potential.